前言：通过浏览器请求文件流进行文件下载这里就不说了，网上有很多例子，这里主要是记录一下工作中的另一个场景，一个服务器通过HTTPClient向另一个服务请求文件流，在内存中进行业务逻辑处理，并不需要下载到本地，当然，如果你想要下载本地也是可以的，把文件流写到本地磁盘就可以了，也可以写到文件系统中。废话不多说。
一，服务器传输的是普通的文件流，没有经过压缩
服务器：
@RequestMapping(value = "/getCommonFile", method = RequestMethod.POST)
public void getFile(HttpServletResponse response) {
BufferedInputStream buffInputStream = null;
OutputStream outputStream = null;
try {
buffInputStream = new BufferedInputStream(new FileInputStream(new File("D:\\testFile\\test.txt")));
outputStream = response.getOutputStream();
byte[] buff = new byte[1024*1024]; //如果是稍微大的文件，这里配置的大一些
int len = 0;
while((len = buffInputStream.read(buff)) > 0) {
//把文件流写入到response的输出流中，供请求端请求
outputStream.write(buff, 0, len);
outputStream.flush();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if(buffInputStream != null) {
buffInputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
try {
if(outputStream != null) {
outputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
客户端：
public void getCommonFile() throws IOException {
//从服务器请求文件流，具体代码就不贴了
CloseableHttpResponse response = HttpSender.toPost(FILE_URL, null);
InputStream inputStream = response.getEntity().getContent();
ByteArrayOutputStream byteArray = new ByteArrayOutputStream();
byte[] buff = new byte[1024*1024]; //如果是稍微大的文件，这里配置的大一些
int len = 0;
while((len = inputStream.read(buff)) > 0) {
//把从服务端读取的文件流保存到ByteArrayOutputSteam中
byteArray.write(buff, 0, len);
byteArray.flush();
}
inputStream.close();
response.close();
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(new ByteArrayInputStream(byteArray.toByteArray()), "utf-8"));
String line = null;
while((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
二，服务器传输的是压缩的文件流（直接读取的压缩文件）
@RequestMapping(value = "/getZipFile", method = RequestMethod.POST)
public void getZipFile(HttpServletResponse response) {
BufferedInputStream buffInputStream = null;
OutputStream outputStream = null;
try {
buffInputStream = new BufferedInputStream(new FileInputStream(new File("D:\\testFile\\test.gz")));
outputStream = response.getOutputStream();
byte[] buff = new byte[1024*1024]; //如果是稍微大的文件，这里配置的大一些
int len = 0;
while((len = buffInputStream.read(buff)) > 0) {
//把文件流写入到response的输出流中，供请求端请求
outputStream.write(buff, 0, len);
outputStream.flush();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if(buffInputStream != null) {
buffInputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
try {
if(outputStream != null) {
outputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
客户端：
public void getZipFile() throws IOException {
//从服务器请求文件流，具体代码就不贴了
CloseableHttpResponse response = HttpSender.toPost(FILE_URL, null);
InputStream inputStream = response.getEntity().getContent();
ByteArrayOutputStream byteArray = new ByteArrayOutputStream();
byte[] buff = new byte[1024*1024]; //如果是稍微大的文件，这里配置的大一些
int len = 0;
while((len = inputStream.read(buff)) > 0) {
//把从服务端读取的文件流保存到ByteArrayOutputSteam中
byteArray.write(buff, 0, len);
byteArray.flush();
}
inputStream.close();
response.close();
//GZIPInputstream解压文件，然后读取文件
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(new GZIPInputStream(
new ByteArrayInputStream(byteArray.toByteArray())), "utf-8"));
String line = null;
while((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
}
三，服务器传输的是压缩的文件流（直接读取的普通文件，然后在内存中将文件流进行压缩）
@RequestMapping(value = "/getCommontToZipFile", method = RequestMethod.POST)
public void getCommontToZipFile(HttpServletRequest request, HttpServletResponse response) {
BufferedInputStream buffInputStream = null;
OutputStream outputStream = null;
GZIPOutputStream zipOut = null;
try {
outputStream = response.getOutputStream();
buffInputStream = new BufferedInputStream(new FileInputStream(new File("D:\\testFile\\test.txt")));
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
//压缩文件
zipOut = new GZIPOutputStream(byteArrayOutputStream);
byte[] buff = new byte[1024*1024]; //如果是稍微大的文件，这里配置的大一些
int len = 0;
while((len = buffInputStream.read(buff)) > 0) {
//把文件流写入到byteArrayOutputStream里面
zipOut.write(buff, 0, len);
zipOut.flush();
}
outputStream.write(byteArrayOutputStream.toByteArray());
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if(buffInputStream != null) {
buffInputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
try {
if(outputStream != null) {
outputStream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
try {
if(zipOut != null) {
zipOut.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
客户端：
和第二种情况的客户端代码一样，就 不贴代码了
四，把多个压缩文件流 写在一个byteArray中
服务端：
@RequestMapping(value = "/getMultiZipFile", method = RequestMethod.POST)
public void getMultiZipFile(HttpServletRequest request, HttpServletResponse response) {
ByteArrayOutputStream byteArray = new ByteArrayOutputStream();
List<File> files = new ArrayList<File>();
File file = new File("D:\\testFile\\test1.gz");
files.add(file);
file = new File("D:\\testFile\\test2.gz");
files.add(file);
for(File file1 : files) {
readDetailDataToByteArray(byteArray, file1);
}
}
public static void readDetailDataToByteArray(ByteArrayOutputStream byteArray, File file) {
BufferedInputStream bufferedInputStream = null;
try {
bufferedInputStream = new BufferedInputStream(new FileInputStream(file));
byte[] b = new byte[1024*1024];
int j;
while ((j = bufferedInputStream.read(b)) > 0) {
byteArray.write(b, 0, j);
byteArray.flush();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if(bufferedInputStream != null) {
bufferedInputStream.close();
}
} catch (Exception e) {
}
}
}
客户端：
和第二种情况的客户端代码一样，就 不贴代码了
public void getZipFile() throws IOException { //从服务器请求文件流，具体代码就不贴了CloseableHttpResponse response = HttpSender.toPost(FILE_URL, null); InputStream inputStream = response.getEntity().getContent(); ByteArrayOutputStream byteArray = new ByteArrayOutputStream(); byte[] buff = new byte[1024*1024]; //如果是稍微大的文件，这里配置的大一些int len = 0; while((len = inputStream.read(buff)) > 0) { //把从服务端读取的文件流保存到ByteArrayOutputSteam中byteArray.write(buff, 0, len); byteArray.flush(); } inputStream.close(); response.close();
//GZIPInputstream解压文件，然后读取文件BufferedReader bufferedReader = new BufferedReader( new InputStreamReader(new GZIPInputStream( new ByteArrayInputStream(byteArray.toByteArray())), "utf-8")); String line = null; while((line = bufferedReader.readLine()) != null) { System.out.println(line); }}
原文地址：https://www.cnblogs.com/jianyong-long/p/9693061.html
时间： 2024-10-30 05:20:18